Apparatus for mixing dental cement



July 25, 1944. N. 1.. WHEELER 2,354,626

APPARATUS FOR MIXING DENTAL CEMENT F}iled May 20-, 1945 2 Sheets-Sheet 36 /3 35 v {9 l4 7 2 J'l;91 l2 I 3 W. i? w Hi y fi- 4- 9 Gigi 27 24 I v INVENTOR 5 40 1 1 A/arfon L Wheele I l Z \J I \J ATTORNEY July 25, 1944. N. 1.. WHEELER APPARATUS FOR MIXING DENTAL CEMENT- 2 Sheets- Sheet 2 Filed May 20, 1945 34 INVENTOR Z [Va/fan LT W/lee/ek ATTORNEY -mllilnllmu HHllll'llllllllillllll. III 1| Patented July 25, 1944 APPARATUS FOR MIXING. DENTAL CEMENT Norton 1L. Wheeler, iTu1sa,"0kla.

AppIicationMayQO, 1943, Serial No 457,199

(crass-1) *8 Claims.

This-invention relatesto an apparatus for mix,- ing dental cement and more-particularly to the mixing of dental cement in air-conditioned re.- ceptacles.

The principal ;-object of thepresent invention is to providefor the.,mixing -of cement under proper temperature and humidity conditions.

It has long been the practiceto use cold instrumentsespecially chilledmixing slabs,- in mixing dentalecement. ;It isalso wellknownthat the use of chilled instruments, when used with either the ox-yphosphateand silicious cements, produces a set cement of superiorwproperties than when uncooled instruments are used. Less haste is necessary inthe mixing procedurecand application of the cement to the teeth in the dental operation. I

In offices having high temperatures, especially in the summer, and inlocalities having arid climates, the cement dies too much and too rapidly for-proper cementmanipulation. This is caused .by the-chilledtslabbecoming warm too quickly and'the evaporation, efiected byithe-larid atmosphere. Furthermore, in humid. climates,. and .in offices heated by open gas stoves, using natural hydrocarbon gas, the atmospheric moisture may condense upon the previously gchilled slab, which condensate, in turn, would be mixed with the cement with detrimentalresults.

I have found that. by, enclosing thechilled slab during the mixingio f the cement thereby decreasing the interchange of radiant heat, and maintaining low-slab temperatures for a much longer period; of time'and byyarious methods of conditioning the enclosed atmosphere around the slab, the ,precipitationwof moisture upon the slab is eliminated and the drying of the cement is controlled. c I

Other objects oi {the invention are, therefore, to provide .for enclosinga chilled dental cement mixing slab .for reducing interchange of .radiant heat; to provide ,a mixing receptacle having transparent panels for the chilled'slab for ;permitting observation of the mixing. operations; to provide the receptaclewith a diaphragm. panel permitting access with and operation of mixing tools for perfor i g the .cem'entmixing. operation; to provide foroiiickhccessto and removal of the mixing slabiromthe receptacle; to provide for conditioning the airlin thereceptacle; to provide for dehydrating or humidifyi-ng ..the. a,ir in the receptacle accor.ding.,to, the climatic conditions; to provide foragitating the air in the receptacle; to provide asturdy. durable and efficient apparatus for the mixingof dentalcement; and

to provide improvedrstructural.elements, and improved arrangements thereof for providing proper conditions. for mixing. .of dental cement.

.In accomplishing these andother objects of the present invention,=I have provided. improved details of structure, the preferred arrangement of which is illustrated in the accompanyin gdrawings, wherein:

Fig. .1 is a perspective viewof a dental cement mixing apparatus embodying the features of. the present invention, particularly illustrating the transparent panels .of the. receptacle.

) Fig. .2 is a plan .view ofthemixingapparatus.

. Fig. .3. is ,a transverse-- sectional -vie.w through themixing apparatus on the line 3-4, Fig.2.

Fig. 4 is a horizontal sectional view through the mixing apparatus on the line 4-.4.,.Fig. 3.

.Fig. 5 is ,an endelevation of the miXing.;.-apparatus, the receptacle and cover therefor .being shown inraised position. for .removal ofthe mixingslab.

Fig. 6 .is a perspective view of {the-dehydrating sheet for the receptacle.

Referring morein detail tothedrawings:

1 indicates av dental cement .mixing. apparatus which ,preierably .includesua base -2 iadaptedto carry the principal portions of the apparatus and preferably forming the. bottom .of .a receptacle '3 which maybe of any convenient-size or shape, but preferably consists of abox-li-ke-arrangement attached to the base by hinges .4, and adapted to enclose a suitable, glass mixing slab ,5. ;The.mixing slabmay be lof -conventional structure .as is commonly used tor the mixing ,of dental cement. I Ilhereceptacle 3 is preferably-of rectangular shape and includes .front,.rear, and side panels 6, 1,18 and 8 respectively, whichlarepreierably formed of any transparent resin;such gas; .phenol f ormaldehyde, vinyl, methyl -metacry'late. cellulose-nitrate or acetate, urea, sterinesorstyrols, orqany-eother transparent substance, .such ,as glass. Metal or other substance may be -u'sedi;or one; .or mor .sides and metal corners -I It or the likemay be used-to attachindividualpanelstogether,.as at II .to simplifythefistructure oflthe receptacle.

. The closure of .the receptacle isv completedby a. cover member [12,, preferably of transparent material, similar to that used in the wa11s of ;the receptacle, said cover being mounted .onlthe. receptablej'by. hinges I 3 which connect the rear edge I' l of the covermemberwith theerear yvall I of the receptacle, whereby the cover member flyfbe hinged upwardly and lrearwardlyaway moisture to prolong the mixing time for the cement in the receptacle.

To prevent excessive moisture from causin condensation on the mixing slab, I have also provided a rigid sheet 35 to which calcium chloride or other hygroscopic agent has been aflixed by non-hydrous cement, such as cellulose acetate and acetone, or impregnated in the sheet in any suitable manner. The sheet is preferably of sub- 'stantially the same length as'the interior of the receptacle 3 and is supported at its end by clips 1136 having inwardly extending flanges 31 and 38 stantial size. The aperture I8 is provided with an air seal which includes a flexible diaphragm '1 [9 which may be of thin semi-transparent rubher, but is preferably formed of plasticized vinyl resin or the like to provide the maximum amount of light in the receptacle. The flexible diaphragm I9 is of larger area than the aperture l8 :1

to provide margins superimposed over the panel 6 and is preferably backed by means of a transparent sheet of plastic material 2| which is'securedto the panel 6 by means 'of suitable fastening devices 22. The flexible diaphragm maybe securedfin a suitable frame and said fra'mesecured to the panel 6 in a conventional manner.

A suitable aperture 23, preferably consisting of a slot is provided in the diaphragm for passage of mixing tools or the like 24 through the diaphragm for manipulation of the cement mix I! on the glass slab, the diaphragm being adapted to form closely around the tool 24 to provide a substantial air'seal and prevent the outside atmosphere from affecting the cement in the receptacle. v

In order to maintain the air in the receptacle under proper temperature and humidity conditions, therear panel I is preferably provided with a tubular connection 25 which is connected by a flexible conduit 26 with a suitable source of air, said air being preferably cooled and dehydrated to a proper degree. The conduit 26 is preferably c'onnected to' a container 21 preferably havinga hygroscopic agent, such as calcium chloride, phosphorous pentoxide, colloidal silicondioxide; or' other suitable agent 28 therein, the container preferably-receiving air from a suitable compressed air sourcethrough a tube 29. The-container 21 may be of any desired shape, however, it is shown as tubular, with the hygroscopic agent confined by perforated members 30 and'3l spacedfrom the ends 32 and 33 ofthe container. The container shown isattachedto the rear portion of the base member by means of-aslip springdevice 34 for easy removal and replacement: The container may be placedon any convenient portion of the unit and rigidly attached if desired. 4

;In normal'climates, there is sufficient humidity increase the tendency for condensation of moispassing thereth'rough would receive suificient 75' to provide grooves 39 adapted to receive the ends of the sheet 35, the sheet preferably having an aperture or the like 40 adjacent the tubular connection 25 to permit free entry of air from the container 21. In order to provide adequate air circulation in the receptacle 3 and proper air flow and. contact over the hygroscopic sheet 35, I provide an agitator 4| preferably including a flat member 42 on the end of a rod 43 which extends through an aperture 44 in the wall 8 of the receptacle, said rod 43 terminating in a knob or suitable handling device 45 for easy manipulation and reciprocation of the agitator 4| in a backward and forward motion to cause suitable air agitation in the receptacle. The amount of air agitation aids the control of the condensation in the receptacle regardless ofthe type of air-conditioning units that might be "attached to the tubular connection 25, or whether any unit is attached-to the connection.

Strips 46 and 41 are provided on the base 2, at each end of the receptacle 3, to aid the hinges 4 in supporting same on the base and preventing lateral movement thereof. The base is also provided with suitable .handles 48 and 49 to provide for easy movementof the apparatus in a dentists ofiice. These strips and handles as well as the other respective parts of the entire apparatus may be fabricated, piece by piece, or may be partly-fabricated and partly molded, or molded entirely, as desired, to provide an attractive and substantial apparatus. 3

In using an apparatus such as described, and particularly for mixing dental cement, the sheet 35, having a hygroscopic material impregnated or otherwise attached thereto, is inserted in the slot 39 in the receptacle, with theaperture 40 in alignment; with the tubular connection 25. The conduit 29 is connected to a suitable air supply and the container 2'! is filled with a dehydrating agent 28'or humidifying agent, as indicated and required by the surrounding atmospheric conditions.- The conduit also is connected to the flexible conduit 26 whereby the air flows from the conduit 29 through the material in the container 2'! to the tubular connection 25, into the receptacle 3 to condition the air therein. The receptacle 3 is then hinged upwardly on the base 2, as shown in" Fig. 5, and the glass mixing slab 5, which has been previously chilled in a suitable refrigerator or the like, is placed therein. The receptacle 3' is then hinged downwardly so that the lower edges 50 seaton the upper surface of the base 2 between the strips 46 and 41, and th cover I2 is hinged downwardly to complete the enclosure of the glass mixing slab. After the glass slab is placed in the receptacle 3, powdered cement ingredients are inserted through the cover aperture l6 onto the surface of the slab 5. Suitable quantities of liquid ingredients are then poured through the aperture I5 and worked into the powdered ingredients by means of mixing tools 24 which are extended through the slot 23 in the flexible diaphragm IS in the front panel 6, suitable panels of the receptacle being transparent to permit adequate light to enter the receptacle and provide proper observation of the mixing operation. The chilled slab, being confined by the receptacle, tends to retain its temperature for a long period of time, particularly if the air supply entering at the connection 25 is cooled, and there would be substantially no condensation in the receptacle even though the glass slab is chilled, since the moisture is controlled by the material in the container 21. If any condensation does appear on the glass slab in the receptacle, it is easily observed by the operator and with proper manipulation of the agitator 4|, the air is circulated past and in contact with the hygroscopic material impregnated in the sheet 5 to further reduce the humidity in the receptacle 3.

After suitable mixing of the cement ingredients, the cover l2 may be lifted to provide access to the receptacle for removal of the cement, easy access to the glass slab also being had to provide for easy removal and cleaning through the open top of the receptacle or by hinging the entire receptacle on the hinge members 4 whereby the slab may be removed from the top of the base member 2, the panel members 48 and 49 permitting easy movement of the apparatus into a suitable cabinet or other storage.

From the foregoing, it is apparent that I have provided an apparatus for enclosing a chilled dental cement mixing slab to reduce interchange of radiant heat, provided for the control of temperature and humidity conditions during the mixing of the cement; and have provided a sturdy, durable and efilcient apparatus for the mixing of dental cement.

What I claim and desire to secure by Letters Patent is:

1. In an apparatus for mixing dental cement, a mixing slab, a receptacle for enclosing said slab, said receptacle having at least one transparent panel for providing a view of the interior of the receptacle, a flexible diaphragm panel in the receptacle, and means extending through the diaphragm into the receptacle for mixing the cement on the mixing slab.

2. In an apparatus for mixing dental cement, a mixing slab, a receptacle for enclosing said slab, said receptacle having openings therein for applying cement ingredients to the slab, means for dehydrating the air in the receptacle, and means extending into the receptacle for mixing the cement ingredients on the slab.

3. In an apparatus for mixing dental cement, a chilled mixing slab, a receptacle for enclosing said slab, said receptacle having openings therein for applying cement ingredients to the slab, means for conditioning the air in the receptacle for reducing condensation of moisture on the chilled slab, and means extending into the receptacle for mixing the cement ingredients on the chilled slab.

4. In an apparatus for mixing dental cement, a mixing slab, a receptacle for enclosing said slab, said receptacle having openings therein for applying cement ingredients to the slab, means for dehydrating the air in the receptacle, a flexible diaphragm panel in the receptacle, and means extending through the diaphragm into the receptacle for mixing the cement ingredients on the slab.

5. In an apparatus for mixing dental cement, a mixing slab, a receptacle for enclosing said slab, said receptacle having openings therein for applying cement ingredients to the slab, a sheet impregnated with dehydrating agents in the receptacle, mean for agitating the air in the receptacle for moving same by the sheet to dehydrate the air, and means extending into the receptacle for mixing the cement ingredients on the slab.

6. In an apparatus for mixing dental cement, a support, a rectangular frame hinged to the support and adapted to seat thereon, a cover hinged on the frame and adapted to cooperate with same to form an enclosure, at least one transparent panel in the frame, a mixing slab in the enclosure, and means extending into the frame for engaging the slab.

'7. In an apparatus for mixing dental cement, a chilled mixing slab, a receptacle for enclosing said slab, said receptacle having openings therein for applying cement ingredients to the slab, said receptacle having at least one transparent panel for providing a view of the interior of the receptacle, means for conditioning the air in the receptacle for reducing condensation of moisture on the chilled slab, a flexible diaphragm panel in the receptacle, and means extending through the diaphragm into the receptacle for mixing the cement on the mixing slab.

8. In an apparatus for mixing dental cement, a support, a rectangular frame hinged to the support and adapted to seat thereon, a cover hinged on the frame adapted to co-operate with same to form an enclosure, at least one transparent panel in the frame, a chilled mixing slab in the enclosure, means for conditioning the air in the enclosure for reducing condensation of moisture on the chilled slab, and means extending into the frame for engaging the slab.

NORTON L. WHEELER. 

